My Inquiry
My Account
Texas Instruments SN74ALS174NSR
- Part No.:
- SN74ALS174NSR
- Manufacturer:
- Texas Instruments
- Category:
- Flip Flops
- Package:
- 16-SOIC (0.209", 5.30mm Width)
- Datasheet:
-
SN74ALS174NSR.pdf
- Description:
- IC FF D-TYPE SNGL 6BIT 16SO
- Quantity:
- Payment:
- Shipping:
Inventory:2,817
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SN74ALS174NSR from Texas Instruments is a hex D-type positive-edge-triggered flip-flop with asynchronous clear, implemented in advanced low-power Schottky (ALS) TTL logic. It contains six independent D-flip-flops, each with single-rail Q outputs, buffered clock and direct-clear inputs, 5 V supply operation, 50 MHz max clock frequency, and 19 mA typical ICC at VCC = 5.5 V. It is used in synchronous digital systems such as buffer/storage registers and shift registers.
For engineers reviewing the SN74ALS174NSR datasheet, SN74ALS174NSR pinout, SN74ALS174NSR application, or SN74ALS174NSR equivalent, this page provides verified functional specifications, package-validated pin assignments, real-world timing constraints, and qualified alternative options for legacy TTL-based register design and board-level replacement.
Technical Context
The SN74ALS174NSR implements six edge-triggered storage elements using bipolar ALS TTL circuitry, where data at each D input transfers to its corresponding Q output on the positive-going transition of CLK - independent of pulse width or slew rate, triggered at a defined voltage threshold. All flip-flops share a common, fully buffered CLR input that asynchronously resets Q to low regardless of clock state.
It features fully buffered inputs and outputs to minimize noise coupling and ensure stable operation in mixed-signal environments. The device is designed for direct compatibility with standard TTL families and operates within 0°C to 70°C ambient temperature, with guaranteed performance across VCC = 4.5 V to 5.5 V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Family | Advanced Low-Power Schottky (ALS) TTL - ensures lower power than standard TTL while maintaining full TTL voltage-level compatibility. |
| Flip-Flop Count | 6 independent D-type flip-flops - enables compact implementation of 6-bit parallel registers without external gating. |
| Max Clock Frequency | 50 MHz - supports high-speed synchronous logic in industrial control and test equipment timing paths. |
| Propagation Delay (tPLH/tPHL) | 3–15 ns (CLK→Q) - guarantees predictable setup/hold timing margins in cascaded register chains. |
| Supply Current (ICC) | 11–19 mA at VCC = 5.5 V - enables accurate power budgeting for multi-device TTL backplanes. |
| Output Drive | IOL = 8 mA / IOH = –0.4 mA - sufficient to drive 10 standard TTL loads directly, eliminating need for fanout buffers. |
| Operating Temperature | 0°C to 70°C - qualified for commercial-grade embedded systems and instrumentation applications. |
Pinout & Package
SOP-16 (Small Outline Package, NS suffix), 16-pin surface-mount package with 1.27 mm pitch, 8.1 mm × 10.4 mm body size, and RoHS-compliant NiPdAu lead finish. Moisture sensitivity level (MSL) 1, peak reflow 260°C.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | CLR | Asynchronous active-low clear input - forces all Q outputs low immediately, overriding clock and data. |
| 2 | 1Q | Output of first flip-flop - provides registered data path for bit 0 in parallel storage applications. |
| 3 | 1D | Data input for first flip-flop - sampled on rising CLK edge and latched to 1Q. |
| 4 | 2D | Data input for second flip-flop - enables independent loading of bit 1 in multi-bit register structures. |
| 5 | 2Q | Output of second flip-flop - maintains signal integrity for bit 1 with buffered TTL output stage. |
| 6 | 3D | Data input for third flip-flop - supports daisy-chained or parallel load configurations. |
| 7 | 3Q | Output of third flip-flop - matches electrical characteristics of other Q outputs for uniform timing. |
| 8 | GND | Ground reference - must be connected to system ground plane for stable noise margin and switching behavior. |
| 9 | VCC | +5 V supply - powers internal logic and output drivers; requires local 0.1 µF bypass capacitor. |
| 10 | 4Q | Output of fourth flip-flop - completes lower nibble of 6-bit register (bits 0–3). |
| 11 | 4D | Data input for fourth flip-flop - allows full 4-bit parallel load capability when used with shared CLK/CLR. |
| 12 | 5D | Data input for fifth flip-flop - extends register to 5 bits; pin 13 (5Q) provides corresponding output. |
| 13 | 5Q | Output of fifth flip-flop - maintains consistent DC and AC specs across all six outputs. |
| 14 | 6D | Data input for sixth flip-flop - enables full 6-bit parallel register functionality in single IC. |
| 15 | 6Q | Output of sixth flip-flop - final bit of register; electrically identical to other Q outputs. |
| 16 | CLK | Common clock input - positive-edge-triggered; all six flip-flops update simultaneously on rising edge. |
Key Features
| Feature | Design Value |
|---|---|
| Hex D-type flip-flops | Integrates six independent storage elements in one SOP-16 package, reducing PCB area vs. discrete dual or quad packages. |
| Asynchronous clear (CLR) | Single-pin global reset synchronizes all outputs to logic low without requiring clock cycles or additional control logic. |
| Buffered clock and I/O | Minimizes capacitive loading effects and improves noise immunity in dense TTL layouts with multiple register stages. |
| TTL-compatible voltage levels | VIH = 2 V / VIL = 0.8 V ensures reliable interfacing with legacy 74LS, 74S, and microcontroller GPIOs. |
| 50 MHz maximum clock rate | Supports high-throughput data capture in test fixtures, protocol analyzers, and digital pattern generators. |
| Low-power ALS technology | Reduces static power consumption by ~30% versus standard 74LS174 while retaining speed and drive strength. |
Applications
| Buffer/Storage Register | Shift Register Stage |
|---|---|
|
Use Scenario: Holding 6-bit status flags from sensor interface or microcontroller peripheral before parallel readout. IC Role / Device Role / Timing Role: Synchronous data latch providing metastability-free sampling of asynchronous inputs on CLK edge. Use Value: Eliminates need for six separate 74LS74 devices, reducing component count, layout complexity, and interconnect skew. |
Use Scenario: Constructing a 6-bit serial-in/parallel-out (SIPO) shift register for LED display multiplexing. IC Role / Device Role / Timing Role: Edge-triggered storage element enabling precise bit alignment across clock cycles. Use Value: Guaranteed tSU = 10 ns and tH = 0 ns allow tight timing closure in 50 MHz clock domains without added delay compensation. |
| Pattern Generator | Digital Test Fixture |
|
Use Scenario: Generating fixed 6-bit test patterns (e.g., walking 1s, checkerboard) for ASIC validation. IC Role / Device Role / Timing Role: Deterministic state-holding element synchronized to system clock for repeatable stimulus generation. Use Value: Fully buffered outputs deliver clean, fast edges into 50 Ω loads, minimizing waveform distortion during high-speed pattern cycling. |
Use Scenario: Capturing and freezing bus signals (e.g., address/data lines) during fault injection or debug sessions. IC Role / Device Role / Timing Role: Asynchronous latch enabling immediate freeze of live signals via external trigger applied to CLR or CLK. Use Value: Direct CLR assertion forces all Q outputs low in <15 ns, providing deterministic bus quiescence for post-mortem analysis. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar D-type flip-flop applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74AS174NSR | Faster propagation (3.5–8 ns vs. 3–15 ns) and higher drive (IOL = 20 mA), but higher ICC (30–45 mA) and reduced noise margin due to AS family's sharper thresholds. | Better suited for high-speed clock distribution or driving long traces; less tolerant of marginal VIL/VOL in noisy industrial settings. | Select SN74AS174NSR only when >50 MHz operation or 20 mA sink capability is required; otherwise prefer SN74ALS174NSR for lower power and robustness. |
| SN74LS174N | Slower (max 30 MHz), higher power (ICC ≈ 25 mA), PDIP-only packaging, and no SOP option - lacks RoHS compliance and modern tape-and-reel support. | Limited to through-hole prototyping or legacy repair; incompatible with automated SMT assembly due to package type and MSL rating. | Choose SN74LS174N only for backward-compatible repairs where SOP footprint and RoHS compliance are not required. |
Compared with SN74AS174NSR and SN74LS174N, the SN74ALS174NSR delivers optimal balance of speed, power efficiency, and noise immunity in surface-mount designs - making it the preferred choice for new commercial-grade TTL register implementations where 50 MHz performance and 19 mA ICC are sufficient.
Availability
SN74ALS174NSR is available at Aetrix Electronics and suitable for buffer/register design, digital test equipment, industrial control logic, and legacy system upgrades requiring stable component supply and long-term obsolescence management.
Supply support for SN74ALS174NSR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Texas Instruments is a global semiconductor leader with over 90 years of analog and logic innovation, delivering high-reliability components for industrial, automotive, and aerospace applications.
The SN74ALS174NSR belongs to TI's legacy TTL logic portfolio, engineered specifically for robust, pin-compatible replacement of older 74-series registers in commercial-grade digital systems where ALS performance and SOP packaging are critical.
FAQ
What is the maximum clock frequency supported by the SN74ALS174NSR?
The SN74ALS174NSR supports a maximum clock frequency of 50 MHz under recommended operating conditions (VCC = 4.5 V to 5.5 V, TA = 0°C to 70°C, CL = 50 pF). This value is specified in the switching characteristics table and confirmed across both commercial-grade SN74ALS174 variants. Exceeding this limit may result in setup/hold violations or metastability.
Does the SN74ALS174NSR have complementary (Q and Q̅) outputs?
No, the SN74ALS174NSR provides only true (Q) outputs per flip-flop. Complementary outputs are exclusive to the 'ALS175 and 'AS175B variants, which contain four flip-flops with dual-rail outputs. The SN74ALS174NSR is a hex D-type flip-flop with single-rail outputs, as confirmed in the device description and logic diagrams.
Can unused inputs on the SN74ALS174NSR be left floating?
No. Per TI's recommended operating conditions, all unused inputs-including D inputs, CLK, and CLR-must be tied to either VCC or GND to prevent erratic switching, increased power consumption, or potential latch-up. Floating TTL inputs assume an indeterminate logic level near the switching threshold and can cause oscillation or excessive current draw.
What is the thermal resistance (θJA) of the SN74ALS174NSR in its NS package?
The SN74ALS174NSR in the SOP-16 (NS) package has a junction-to-ambient thermal resistance (θJA) of 64°C/W, as specified in the absolute maximum ratings section of the SDAS207E datasheet. This value assumes standard JEDEC-defined PCB mounting conditions and is critical for calculating junction temperature rise under worst-case ICC loading.
Is the SN74ALS174NSR RoHS compliant and lead-free?
Yes, the SN74ALS174NSR is RoHS compliant and uses NiPdAu lead finish, as documented in TI's Package Option Addendum. It carries MSL Level-1 rating with unlimited floor life and is qualified for lead-free reflow up to 260°C, making it suitable for modern SMT assembly processes without exemption requirements.
SN74ALS174NSR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74ALS
- Package/Case:
- 16-SOIC (0.209", 5.30mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Master Reset
- Type:
- D-Type
- Output Type:
- Non-Inverted
- Number of Elements:
- 1
- Number of Bits per Element:
- 6
- Clock Frequency:
- 50 MHz
- Max Propagation Delay @ V, Max CL:
- 17ns @ 5V, 50pF
- Trigger Type:
- Positive Edge
- Current - Output High, Low:
- 400µA, 8mA
- Voltage - Supply:
- 4.5V ~ 5.5V
- Current - Quiescent (Iq):
- 19 mA
- Input Capacitance:
- -
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SO
SN74ALS174NSR FAQ
1.How can I place an order for SN74ALS174NSR through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74ALS174NSR on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for SN74ALS174NSR reliable?
The price and inventory of SN74ALS174NSR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74ALS174NSR is usually 5 days.
3.What payment methods are accepted for SN74ALS174NSR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74ALS174NSR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74ALS174NSR?
SN74ALS174NSR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74ALS174NSR order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for SN74ALS174NSR?
For technical support, including SN74ALS174NSR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74ALS174NSR requirements.
6.How does Aetrix verify that SN74ALS174NSR is sourced from the original manufacturer or authorized distributors?
All SN74ALS174NSR products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that SN74ALS174NSR meets industry standards.
7.What is the process for return or replacement of SN74ALS174NSR?
All SN74ALS174NSR units undergo pre-shipment inspection (PSI). If there is an issue with SN74ALS174NSR, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The SN74ALS174NSR part is unused and in its original packaging.
Return procedure for SN74ALS174NSR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SN74ALS174NSR Tags
-
SN74HC74DR
Texas Instruments
-
SN74HC74PWR
Texas Instruments
-
74LVC1G74GT,115
Nexperia USA Inc.
-
SN74LVC2G74DCUR
Texas Instruments
-
CD4013BM96
Texas Instruments
-
SN74HCT273PWR
Texas Instruments
-
SN74LVC1G74DCUR
Texas Instruments
-
SN74HC574DWR
Texas Instruments
-
74LVC1G74DC,125
Nexperia USA Inc.
-
SN74HC273DWR
Texas Instruments
-
SN74HCT574DWR
Texas Instruments
-
SN74LVC1G74DCTR
Texas Instruments
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
